—Voting is the process through which a democratic society determines its government. Therefore, voting systems are as important as other well-known critical systems, such as air traffic control systems or nuclear plant monitors. Unfortunately, voting systems have a history of failures that seems to indicate that their quality is not up to the task. Because of the alarming frequency and impact of the malfunctions of voting systems, in recent years a number of vulnerability analysis exercises have been carried out against voting systems to determine if they can be compromised in order to control the results of an election. We have participated in two such large-scale projects, sponsored by the Secretaries of State of California and Ohio, whose goals were to perform the security testing of the electronic voting systems used in their respective states. As the result of the testing process, we identified major vulnerabilities in all the systems analyzed. We then took advantage of a comb...